1. Field of the Invention
The invention pertains to the field of apparatus for preparation of medicines. More particularly, the invention pertains to methods and apparatus for crushing and dissolving pills and tablets
2. Description of Related Art
Young children and old people often have difficulties swallowing solid medications. In some institutional settings such as prisons, regulations prevent distribution of medicines in solid form. Therefore, there is a need for disintegrating and dissolving solid medicine or solid-encased liquid-filled medicines (pills, caplets, liquid-gels, and tablets-hereinafter “p/t”) so that the medicine can be administered in liquid form.
Pill/tablet dissolvers are used in hospitals to help administer solid medication to people who have difficulties in swallowing solid medication. These devices are also used in nursing homes and correctional facilities.
Many prior art manual dissolvers use some sort of hand crushing. This method has numerous disadvantages: It cannot disintegrate the coating of the p/t and they float as large flakes on top of the liquid. It is a very tedious process. It does not dissolve the p/t to very small homogeneous particles. Significant part of the p/t material is left behind in the package where the p/t were crushed. Mixing with the liquid is insufficient.
Other prior art dissolvers use ultrasound. Ultrasound methods also have numerous disadvantages. The time to dissolve p/t depends on the p/t size and it can vary from 20 sec to 60 sec. It requires long time and high power ultrasound horn for large p/t which causes the liquid in the cup to heat up, making it unpleasant to drink. The ultrasound can not dissolve many of the different coating materials. As a result, the broken coating material floats on top of the liquid. The ultrasound requires high power to operate. It cannot be operated on batteries and thus is not portable. Furthermore, ultrasound pill dissolving methods are expensive.
Several prior art devices use mechanical means to crush medicines. U.S. Pat. No. 5,531,386 describes a pill pulverizer apparatus which is sized to loosely receive a folded envelope containing the dry medicine to be crushed. A hammer is withdrawn by a motor, thereby compressing a spring. The pill pulverizer automatically detects the insertion of the envelope and then the hammer is released and propelled against the envelope breaking the medicine inside apart in one short blast. The crushed dry medicine may then be poured out of the envelope into a second container where it can be mixed with water. Such a system results in extra waste from needing a second container, and the likely possibility that some of the crushed medicine will remain stuck in the corners of the envelope, resulting in inaccurate dosage for a patient. Additionally, if such a system was used to crush hard-covered liquid-filled gels, the liquid medicine would coat the inside of the envelope and not pour completely into the secondary container, thereby resulting in possibly a more inaccurate patient dosage.
U.S. Pat. No. 5,376,072 describes an apparatus and method for crushing a pill and administering the pill ingredients. A pill is placed in a syringe barrel, and then a syringe plunger is placed into the barrel, and pressed and optionally grinded against the pill to crush it. An inlet/outlet tube is provided on the barrel, so that the plunger may be withdrawn to pull liquid into the barrel for mixing with the crushed medicine. The crushed medicine/liquid mixture may then be plunged out of the inlet/outlet tube. In some embodiments, the entire plunger/barrel crushing mechanism is only good for one crushing due to contamination. In other embodiments, a disposable insert is provided for the barrel and a disposable insert is provided for the plunger.
U.S. Pat. No. 5,067,666 describes a portable pill crusher which has a crushing ram which is normally spring biased away from a crushing area. A cup containing pills for crushing may be placed into the crushing area. An eccentric wheel on a motor forces the ram down into the top opening of the cup and into a relatively slow crushing contact directly with the medicine. Since the ram directly contacts the medicine, it must be cleaned between every use with an alcohol-soaked swab to remove remaining medicine. Additionally, this remaining medicine on the ram may result in inaccurate dosage to patients.
U.S. Pat. No. 6,622,949 describes a portable, solenoid-driven medicine crusher. An outer cup contains dry pills for crushing, and an inner cup is placed within the outer cup to cover the pills. This dual-cup may be placed into the crushing area. A ram is forced down into the top opening of the inner cup by a solenoid, thereby crushing the dry medicine between the inner and the outer cups. The need for a second cup for each crushing results in a system which has extra waste. Additionally, as in all the above systems, liquid is added to the crushed medicine after the medicine has been crushed.
Thus, there is a need for a pill dissolver which must be able to dissolve all kinds and shapes of pills, tablets or caplets. The pill dissolver should be able to dissolve the medicine to small particles, including all the different coating on the p/t. The pill dissolver must be able to convert solid medication to a well mixed liquid, and must be able to complete the whole dissolving cycle quickly—preferably in less than 20 sec. In some applications, the pill dissolver must be portable with an optional battery operation. The pill dissolver should be small in size and low cost, and must reduce waste. The pill dissolver must also provide accurate dosage by not leaving crushed medication behind.